<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <link rel="stylesheet" href="./layui.css">
    <script src="./layer.js"></script>
    <style>
        .red {
            background-color: red;
        }
    </style>
</head>

<body>
    <div class="layui-container">
        <div class="layui-row">
            <div class="layui-col-md3 red">
                1
            </div>
            <div class="layui-col-md3 red">
                1
            </div>
            <div class="layui-col-md3 red">
                1
            </div>
            <div class="layui-col-md3 red">
                1
            </div>
        </div>
    </div>
</body>

</html>